Ions are often used during manufacturing of semiconductor devices. For example, ions may be implanted into a substrate to dope the substrate with various impurities. Ions may be deposited onto a substrate to build up features on the substrate. Ions may also be used to etch away material during the manufacturing process. In general, ions are emitted from an ion source chamber. Magnets are often used to filter the ions and also shape the ions into an ion beam having intended characteristics and direct the ion beam at the substrate. Some of these magnets are formed by wrapping conductive wire around a metal core. Current is then passed through the conductive wire to create a magnetic field. During operation, the magnets often need cooling in order to operate at the power levels necessary to create magnetic fields having intended characteristics. As such, a cooling passage is formed in the metal core for passing cooling fluid during operation. One deficiency in some current designs stems from a cooling passage used at the centerline of the core. As such, heat generated in the windings is be conducted through the thickness of the core in order to reach the cooling fluid. The removal of a relatively large amount of material in order to form a cooling passage of requisite size, as will be appreciated, reduces the amount of material in the metal core and undesirably reduces the strength and effectiveness of the magnetic field created by the magnet. Thus, there is a need for an improved cooling arrangement for magnets used in substrate processing operations.